Railway block-signal system.



W. M; CHAPMAN.

RAILWAY BLOCK SIGNAL SYSTEM.

APPLICATION FILED FEB. 26. 1913.

Patnted- 0015.15, 1918;.

3 SHEETS-SHEET 1- W. M. CHAPMAN.-

RAILWAY BLOCK SIGNAL SYSTEM.

APPLICATION FILED FEB. 25. i913" Patented Oct. 15, 1918 3 SHEET$SHEET 2 mswm W. M. CHAPMAN.

RAILWAY BLOCK SIGNAL SYSTEM.

APPLICATION mm) FEB. 26. I913 1 ,28 1 ,5 l 5 Patented Oct. 15, 1918'.

3 SHEETSSHEET 3.

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WINTHROP lVI. CHAPMAN, OF NEEDHAM, MASSACHUSETTS.

RAILWAY BLOCK-SIGNAL SYSTEM.

Application filed February 26, 1913.

To all whom it may concern:

Be it known that I, WVINTHROP M. CHAP- MAN, a citizen of the United States, residin at Needham, in the county of Norfolk an State of Massachusetts, have invented certain new and useful Improvements in Railway Block-Signal Systems; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The present invention relates to railway block signal systems and is designed particu larly for use on single track electric railways, although certain features of the invention are not limited to use in connection with a single track road. The preferred embodiment of the present invention hereinafter described is an improvement on signal apparatus and systems heretofore patented by me, and particularly an improvement on the apparatus and system disclosed in Patent No. 865,013, dated September 3, 1907. It is to be understood, however, that except as defined in the claims, the several features of the present invention are not limited to use in connection with any particular form of signal apparatus or system.

The objects of the present invention are to improve the construction and arrangement of signal actuating mechanism; to improve the construction of the apparatus and the arrangement of the circuit connections of a signaling system employing only two line wires so as to enable a car in backing out of the entering end of a block to count off a car; and to permit a car to enter a block against a danger signal and then back 01f of the block without interfering with the operation of the signals.

With the above objects in view, the present invention consists in the devices, combinations and arrangements of parts. and the constructions and circuit connections hereinafter described and claimed, the advantages of which will be obvious to those skilled in the art from the following description.

Referring to the drawings Figure 1 is a view in front elevation of the improved form of signal apparatus illustrating particularly the signal with its actuating mechanism and the mechanical con-.

Specification of Letters Patent.

Patented. Oct. 15, 1918.

Serial No. 750,862.

struction of the devices for controlling the operation of the signal;

Fig. 2 is a detail view illustrating the latch and associated parts which form a portion of the apparatus which permits a car to enter the distant end of the block against a danger signal without interfering with the operation of the signals;

Figs. 3 and 4 are detail views similar to Fig. 2, but showing the parts in different positions;

Figs. 5 and 6 are diagrammatic views illustrating the arrangement of the apparatus and circuit connections for one block of a single track electric street railway and Fig. 7 is a detail view of the signal actuating cam.

The general arrangement of the circuit connections and the general operation of the apparatus of the signaling system illustrated in the drawings is the same as that of the system illustrated in Patent No. 865,013 and will be readily understood without an eX- tended detail description thereof. The system illustrated in the drawings comprises a signal apparatus at each end of a track section or block, the signal apparatus and their circuit connections being duplicates of each other. Th signal apparatus are connected by two lines wires and these line wires in connection with the trolley wire and rail are utilized to convey the currents by which the signal setting and restoring magnets are energized. Trolley operated switches are provided at each end of the block, which switches are operated by cars going in both directions. Each apparatus comprises a single signal and the entrance of a car on to the block causes the signal at the distant end of the block to be set at danger and the signal at the entering end of the block to be set at safety The entrance of a second car on to the block before the first car leaves the block causes an inclicating movement of the signal at the entering end of the block and actuates a controller which prevents the restoration of the signals until the last car leaves the block. As the cars pass out of the block at the distant end, the controller at the entering end of the block is actuated, and when the last car leaves the block the signals are returned to normal or clear position.

In the improved signal apparatus illustrated in Fig. 1, the signal consists of a semaphore arm 1 arranged to move in a vertical plane in front of a suitable background and secured to a short horizontal shaft 2 suitably supported above the signal box proper. The shaft 2 is provided with a crank arm 3 which is connected by means of a rod 4 to a crank pin on a cam 5 secured to a horizontal shaft in the lower portion of the signal box 6. The normal or clear position of the semaphore arm is that indicated in Fig. 1 in which the arm is inclined clownwardly at an angle of about forty-five degrees. To indicate danger the arm is designed to move to a horizontal position, and to indicate safety it is designed to move to a substantially vertical position. The semaphore arm is also designed to move from safety to clear position and then return to safety position to indicate an actuation of the controller when a car enters the block while the signal is at safety. The arrangement of the connecting rod at with relation to the cam 5 and shaft 2 is such that the desired movements can be imparted to the semaphore by a rotation of the cam, a clockwise movement of the cam operating to swing the semaphore from clear to danger position, and a counter-clockwise movement of the cam operating to move the semaphore arm from clear to safety, and then a continued counter-clockwise movement oper ating to swing the arm back from safety to clear position. The semaphore arm thus has three different positions and these three positions correspond to four positionsof the cam 5. To actuate the cam 5 so as to move the semaphore arm to the desired positions when cars enter and leave the block, two levers, 6 and 7, are provided, centrally pivoted on studs projecting from the back of the box casing and provided at their inner ends respectively with. rolls 8 and 9. These rolls engage a groove 10 formed in the cam and so shaped that when the outer end of the lever 7 is raised the cam is rotated counter-clockwise and when the outer end of the lever 6 is raised the cam is rotated clockwise. When the outer ends of both levers 6 and 7 are down, as indicated in Fig. l, the two rolls 8 and 9 are near the center portion of the cam and the semaphore arm is in the clear position. As will be obvious from an inspection of the figure, the upward movement of the outer end 'of lever 6 will cause the roll 8 to move down the right hand portion ofthe cam groove and swing the cam. in a clockwise direction to move the semaphore arm to danger position. During this movement of the cam, the roll 9 rev mains at rest and travels in a substantially concentric portion of the cam groove. In like manner, starting with the parts in the position illustrated in Fig. 1 if the outer end of the lever 7 is raised the roll 9 travels along the left hand portion of the cam groove 10 and the cam 5 is turned counterclockwise far enough to move the semaphore arm to safety position. When the roll 9 is in its lowest position it will be located just at the outer end of the cam groove 10. If now while the outer end of lever 7 still re mains raised the outer end of lever 6 is raised, the roll 8 will travel along the left hand portion of the cam groove 10 and the cam will be swung still farther counterclockwise so as to move the semaphore arm from its position at safety to its clear position. During this movement of the cam the roll 9 travels along the outer periphery of the cam beyond the end of the cam groove. The levers 6 and 7 are actuated in the same manner as the corresponding levers of the apparatus of Patent No. 865,013, the levers being pivotally connected respectively to the lower ends of rods 11 and 12 projecting downwardly from the cores of magnets 13 and 14. In addition to the rolls 8 and 9 the levers 6 and 7 are also provided with rolls 15 and 16 which are arranged to engage the outer periphery of the cam 5. The shape of the outer periphery of the cam and of the cam groove 10 is such that the cam is securely locked against movement in all positions and thus tampering with the signal mechanism by manual manipulation of the semaphore arm is prevented.

The magnets 13 and 14, illustrated in Fig. operate in the same manner as the corresponding magnets of Patent No. 865,013, magnet 13 of the apparatus at the distant end of the block being energized to set the distance signal at danger, and magnet 14 at the entering end of the block being energized to set the signal at the entering end of the block at safety when the first car enters the block, and being thereafter energized each time a car leaves the block to actuate the controller or to return. the sig nals to clear position. In addition to the mechanism above described, there is also illustrated in Fig. 1 a magnet 17 which is energized each time a car enters the block, a

pawl carrying lever 18 actuated through a rod 19 from the core of magnet 17, a lock ing lever 20 for the core of magnet 14. and controlling and unlocking mechanism actuated by the pawl carrying lever 18 and by the rod 12 and core of magnet 14. These parts have substantially the same construction and mode of operation as the corresponding parts of Patent No. 865,013. The lever 21,however, which holds the pawl 22 out of engagement with the ratchet wheel when the magnet 17 is energized by the en trance of the first car on the block, is made separate from the contact carrying lever 28.

The lever 23 is mounted upon the shaft of the ratchetwheel and is provided with a tooth which is covered by the lever 21 when the parts are in the position indicated in Fig. 1 so that the contact carrying lever 23 is not actuated by the entrance of the first car on to the block. As soon as the rod 12 is raised,however, and the signal at the entering end of the block isset, the lever 21 moves out of engagement with the pawl 22 and uncovers thetooth of the lever 23 so that the lever23 is actuated each time a car enters the block after the signal has been set at safety. The object of this change in construction will be explained hereinafter.

In the apparatus illustrated in Patent No. 865,013 asomewhat complicated system'of contacts was provided for maintaining magnet 14 energized until magnet 17 was deenergized when 'cars entered and left the block simultaneously so as to insure the proper actuation of the controllerr In the constructionillustrated in Fig. 1 these extra contacts are done away with and a latch 24 is provided pivoted upon a stationary part of the casing and arranged to engage the inner end of the lever 26 to which the es capeinent pallet is yieldingly connected and which in the present construction also serves to hold the locking lever 20 out of the path of the locking shoulder on the rod 12 when the signal is returned to normal position. After the signal is set at safety the arm 26 is moved each time a car leaves the block to operate the escapement pallet so'as to allow the ratchet wheel of the controller to move backwardly one step; The latch 24 is normally held by engagement with the core of magnet 17 in position so that it does not engage the rearwardly projecting lug on the lever 26. In case both the magnets 17 and 14 are energized simultaneously as they will be when cars enter and leave the block simultaneously, the latch 24 is released and at the same time the lever 26 is actuated so that the latch'24 swings overan-d engages the lug on the lever 26. The lever 26, to-

gether with the escapement pallet is thus held in the position to which it has been moved by the upward movement of thecore of magnet 14 after the magnet 14 is deencrgized, and remains in this position until the magnet 17 is (le'e'nergized. The ratchet wheel of the controller is thus moved forward a step when the magnet 17 is energized, but is not retained in this position by the pallet and is allowed to return to its former position. The engagement of the latch 24 with the lever 26 therefor -insures a proper actuation, which in effect is no actuation at all ofthe controller when cars enter and leave the block simultaneously.

Referring now to Figs. 5'and 6,it will be seen that the circuit connections and contacts have the same general arrangement as those of Patent No. 865,013, but that certain changes have been made tending toward simplicity and efficiency of operation. It is believed that the arrangement of the circui-ts and contacts willbe sufficiently under stood from the following description of the operation of the apparatus as a whole when cars enter and leave the block. In. Fig. 5 the apparatus at one end of the block is indicated at A and in Fig. 6 the apparatus at the other end of the block at B. Except for an auxiliary restoring circuit hereinafter referred to the apparatus, circuit connections, and contacts at A and B are duplicates of each other. 27 indicates the trolley wire, 28 the rail, 29 one line wire, and '30 the other linewire. Line wire 29 is connected at apparatus A to contact plate 31 on lever 6 and is connected at apparatus B to contact plate 32 on lever 7. In like manner, line wire 30 is connected at apparatus A to contact plate 32 on lever 7 and at apparatus B is'connected to contact plate 31 on lever 6. Contact plate 32 at each apparatus when the signals are at clear position engages a contact 33 which is connected to the trolley wire through the following connections; wire 34, wire 35, magnet 13, wire 36, contact'plate 37 on lever 18, contact 38 and wire 39. Line wire 29 is thus normally connected to the trolley wire at apparatus B and line 30 is normally connected with the trolley wire at apparatus A. lVhen a car enters the block at apparatus A going toward B a contact 40 is momentarily closed at the trolley switch and a current passes through magnet 17 of apparatus A from the trolley wire 27 tothe rail 28. The lever 18 is actuated and the contact plate 41 on the lever bridges the contacts 42 and 43. The closing of these contacts establishes a circuit from line wire 29 which is connected to the trolley wire 27 atapparatus B through magnet14 of apparatus A to the rail. 28 as follows: Contact plate 31, contact 44, wire 45, contact plate 46v on looking lever 20, contact 47, wire 48, contact 42-and 43, wire 49, wire 50, magnet 14 and wire 51. The core of magnet-14 is thus raised and through the rod 12 and arm 7 the cam 5 is rotated to swing the semaphore arm to safety position. As the core of .magnet 14 rises, the locking lever 20 drops into locking position, thereby separating contact plate 46'and contact-47. This breaks the circuit of magnet 14 and the rod 12 drops until stopped by the locking lever. At apparatus B the magnet 13 is energized simultaneously f with the energization of magnet 14 of'apparatus A so that the signal at apparatus B goes to danger. When the locking lever at apparatus A drops into locking position," the contact plate 46 engages contacts 52 and '53. The circuit sition will cause the return to normal position of the signal at the distant end of the block. While the signal at apparatus A is in safety position the contact plate 32 is in engagement withcontact 55, which contact is connected by av wire to wire 50, which leads to the magnet 14. The line wire 30 is thus connected at apparatus A to the rail 28 through magnet 14. When acar passes out of the block at B, contact is made by the trolley switch at 56, thus connecting the trolley wire '27 to the line 30 and energizing magnet 14 at the entering end of the block. The current passes from the trolley wire 27 to the line wire 30 through the wire 57, contact plate 58, contact 59, wire 60 contact plate 61 and contact plate 31, which at this time is in engagement'with contact plate 61. Each time a car leaves the block therefor, the magnet 14 at the entering endof the block is energized, and when the last car leaves the block the signals are re turned to normal position. In case a second car enters the block. before the first car leaves the block, magnet 17 of apparatus A is again energized. The contact carrying arm 28 is now actuated and contact plate .62 is brought into engagement with contact 63, and contact plate 37 on lever 18 is brought into engagement with contact 64. I This connects one terminal of magnet 13 of apparatus A to the rail through wire and connects the other terminal to'the line Wire 29 through thewire 35, contacts 6362, wire 66, contacts 53-52 and wire 67. The magnet 13 of apparatus A is thus energized momentarily and the semaphore of apparatus A is moved from safety to clear position and then back again to safety.

The reason'for not moving the arm 23 when the first car enters the block will now be apparent. By holding the arm 23 against movement when the first car enters the block the contacts 62 and 63 arenot brought into engagement and consequently the magnet 13 at the entering end of the block is not energized.

Itis desirable in some instances to permit a car which has entered the block to back of]? of the block. In such a case it is necessary that the signal controlling andunlocking mechanism be actuated by the engagement of the trolley with the trolley switch. To permit this to be done without the use of athird line wire, apparatus A. illustrated in the drawlngs is provided with an ttllXlllttly magnet 68 arranged to act on the core of magnet 1 1 14:.

One terminal of this magnet is connected to a contact 69 and the other terminalsis 57 to the trolleycontact 56 which is closed when a car leaves theblock. After the sig nal at the entering end of the block has been set at safety therefor, a car backing out of the block will close a' circuit from the trolley wire to the rail through the auxiliary magnet 68 and actuate the controlling and unlocking mechanism and thereby count ofi' a car in the, same manner that a car is counted offdwhen it leaves the block at the distant en In apparatus B, as illustrated in Fig. 6, the same result is accomplished without the use of an auxiliary magnet by extending the contact plate'32 on the upper side of the lever 7 so that when the. lever 7 is raised, the contact plate will engage the contacts 58 and 55. As has been described, the contact 58 is connected to the'trolley contact 56 which is.

closed when a car leaves the block. The bridging of the contacts 58 and 55 establishes a local or auxiliary circuit including the contact 56 and the'signal restoring magnet 14. v

The signal-system illustrated in the drawings has provision for permitting a car to enter a block against a danger signal and to back out of the block without removingthe trolley wheel from thetrolley wire In the arrangement showna'car entering a block against a danger signal causes the semaphore arm to return nearly to normal position, and at the same time disconnects the wire through which the apparatus at the entering end of the block is actuated to count off a car when a car leaves the block. The semaphore arm remains in its normal position until the car which has entered against the danger signal backs out of the block, when the signal is returned to its position of danger. To secure these results a latch is provided which cotiperates with the lever 18 and with the core of magnet 13. An

auxiliary magnet is also provided for actuating or controlling the operation of the latch. The latch is pivotally mounted on a stationary part of the casing at 70, and is composed of two parts 71 and 72 connected by a spring 7 3. coiled around the pivot stud 7 O. The relative movement of the two parts '71 and 72 under-the force of the spring is limited by a pin 74: on the part 72 and a lug 75 on the part 71. The part 71 is pivotally connected to the lower end of a rod 76, the upper end of which is connected to the core of an auxiliary solenoid magnet 97. The portion 72 of the latch is provided with rearward extensions 77 and 78 which cooperate with a pin 79 projecting from the side of. the rear portion of the lever 18. The portion 71 of the latch is arranged beneath the core of magnet 13, and is in a position to be engaged by a pin 80 on the rod 11 during the upward movement of the core of magnet 13. The normal position of the latch is indicated in Fig. 1. WVith the latch in this position, the pin 79 on the lever 18 is at the right of the latch, and in case the magnet 17 is energized by the entrance of a car into an empty block the lever 18 will be actuated and returned to its normal position as the magnet is deenergized. When the signal is in the danger position, however, the core of magnet 13 is up, and the pin 80 is in engagement with the part 71 of the latch. The pin holds the latch somewhat above its normal position, as indicated in Fig. 2. With the latch in this position the projection 78 on the part 72 of the latch is below the pin 79 on the lever 18. When the car enters the block against the danger signal the magnet 17 at the end of the block is energized, the lever 18 is actuated, and the pin 79 passes down to the left of the projection 78 on the part 72 of the latch. The pin '79 displaces the latch somewhat to the right, and as the pin reaches its lowest position the latch swings in over the pin and holds the lever in the position to which it has been moved by the magnet 17. The actuation of the lever 18 by the magnet 17 breaks the circuit of the magnet 13, so that the core of the magnet drops. The downward movement of the core is limited by contact with the latch, so that the semaphore arm moves nearly to normal position. The core does not drop, however, far enough to bring the plate 31 on the lever 6 into engagement with the contact 1 1. The downward movement of the outer end of arm 6 breaks the circuit at 31, 61, through which the controlling and unlocking mechanism at the entering end of the block is actuated by a car leaving the block, and connects the auxiliary magnet 97 in a circuit which will. be closed when the trolley switch is actuated by the car leaving the block. When the car leaves the block the circuit is closed from the trolley wire 27 through the auxiliary magnet 97 to the rail 28 as follows: contact 56, wire 57, contact plate 58, contact 59, wire 60, contact plate 61, contacts 81 and 82, contact plate 83, wire 84, magnet 97 and wire 85. The energizing of magnet 97 swings the lower end of the latch to the right, so that the pin 79 escapes from the projection 78 on the latch and engages the projection 77. As soon as the trolley contact is opened the magnet 97 is deenergized, the lower end of the latch swings to the left, and the pin 79 escapes from the projection 77, allowing ,the lever 18 to return to its original position. This again closes the circuit of magnet 13, and the signal returns to its danger position.

The nature and scope of the present invention having been indicated, and the preferred form of the invention having been specifically described, what is claimed is j 1. A railway block signal system, having, in combination, a signal, a' cam, means for moving the cam to four different positions, and connections between the cam and the signal acting to move the signal to three different positions when the cam is moved to its four positions.

2. A railway block signal system, having, in combination, a cam, levers pivoted on axes parallel to the aXis of the cam, pins on the levers engaging the cam acting when the levers are actuated separately to rotate the cam in opposite directions and when the levers are actuated successively to rotate the cam in the same direction, a signal, and connections between the cam and the signal for moving the signal to different positions.

3. A railway block signal system, having, in combination, a cam provided with a groove, levers pivoted on axes parallel to the axis of the cam, pins on the levers engaging the groove in the cam and the periphery of the cam acting when the levers are actuated successively to move the cam from normal position in opposite directions and to lock the cam against rotation in the normal position of the cam and in the positions to which it is moved, a signal, and connections between the cam and the signal for moving the signal to different positions.

4. A railway block signal system, having, in combination, a signal apparatus at each end of a block, means to set a signal at safety at the entering end of the block and asignal at danger at the distant end of the block when a car enters an empty block, a restoring circuit including a trolley switch contact at the distant end of the block arranged to be operated by cars leaving the block, an auxiliary circuit, means to disconnect the trolley contact from the restoring circuit and to connect the trolley contact with the auxiliary circuit when a car enters the distant end of the block against a danger signal, and means controlled by the auxiliary circuit operating when the car backs out of the block to again render the restoring circuit operative.

A railway block signal system, having, in combination, a cam, levers pivoted on axes parallel to the axis of the cam, pins on the nections between the cam and the signal for levers engaging the cam aclting when the. moving the signal to different positions. levers are actuated se arate y to move t1e i cam from normal in ogposite directions and A WIN EHROP CHAPMAN 5 to look the cam against rotation when the Witnesses:

oam is in normal position and in the posi- I BURTON W. CARY, tions to which it is moved, a signal, and con- FRED O. FISH.

Copies of this patent maybe obtained for five cents each, by addressing the Commissioner of Patents,

1 Washington, I). 0. 

